Electrothermal Instability or Velikhov instability

The electrothermal instability is a turbulence in the electron gas of a bi-temperature non-equilibrium plasma (ie: when the electronic temperature exceeds the ionic one) subject to strong magnetic fields.

It appears when the Joule effect locally transfers energy to the electronic gas and when that energy can’t be dissipated by the collisional mechanism.

 

Guiding a streamer by magnetic confinement

 

Guiding 3 parallel streamers by magnetic confinement

 

The cancelation of the electrothermal instability is a major prerequisite to any further development of MHD systems applicable to high altitude hypersonic aircrafts.